In the past there have been various types of angiographic catheters. Generally speaking, such cathethers are utilized for diagnostic purposes. More particularly, such a catheter is inserted into an artery or vein and advanced in a generally axially direction through the vessel to a predetermined site as determined by an attending physician for the purpose of injecting radio opaque material. The radio opaque material should be injected under a relatively high pressure to achieve a relatively high concentration in a short period of time so that the images which are achieved in the conventional manner are as sharp as possible.
It will be appreciated by those in the art that such catheters must be quite rigid. This is required to be capable of advancement by pushing, to be susceptible to axial movements of adjustment and to resist twisting or torque forces. Such catheters must also be able to withstand a high bursting pressure while, at the same time, the tip should be as soft as possible so as not to cause injury to the interior wall of the vessel as it is advanced.